Extranl script with Ajax and UI Dialogs close immediately

Hi everyone,

I have a script who work perfectly as an inline script :

<script>
// jqn() is a custom utility finction that escape dots for allowing jquery to find items with dots

$(document).ready(function(){
 $(jqn('#lnk.addnote')).click(function(){
         $.get('/webapp/ui/parts/notes/add.html', function(data) {
 var dlg = $("<div class=\"dialogcontainer\"></div>").append(data);
 $(dlg).dialog({bgiframe: true, modal: true,
 buttons : {
 'Annuler' : function(){
 $(dlg).dialog('close');
 },
 'Créer' : function(){
 var datas = $(dlg).find('form').serialize();
 alert('POST : \n/edu-webapp/ui/parts/notes/add.html?'+datas);
 $.post('/webapp/ui/parts/notes/add.html?'+datas, function(fragment) {
 alert('RECEIVED : \n'+fragment);
 alert('EMPTY : \n'+$('#lstnotes'));
 $('#lstnotes').empty().append(fragment);
 alert('CLOSE DIALOG');
 $(dlg).dialog('close');
 });
 } 
 },
 title: 'Add note'
 });
 });
 return false;
 });
});
 </script>

I have tried to externalize it :

var Notes = {
   add : function() {
       alert("ADD FIRED");
       $.get(CONTEXT+'/ui/parts/notes/add.html', function(fragment) {
           alert("CREATING DIALOG");
           var _dlg = $('<div class="dialogcontainer"></div>').append(fragment);
           // Tip to enable expression evaluation for buttons label
           var _buttons = {};
           _buttons[Tsl.translate('label.Cancel')] = function() {
                   alert("CLOSE DIALOG");
                   $(_dlg).dialog("close");
               };
           _buttons[Tsl.translate('label.Create')] = function() {
                   var values = $(dlg).find('form').serialize();
                   alert("POST \n"+values)
                   $.post(CONTEXT+'/ui/parts/notes/add.html?'+values, function(response) {
                       alert("UPDATING "+$('#lstnotes'));
                       $('#lstnotes').empty().append(response);
                       alert("CLOSE DIALOG");
                       $(dlg).dialog('close');
                   });
               };
           $(_dlg).dialog({bgiframe: true, model: true, buttons: _buttons,
               title: 'TO i18n'});
       });
   }

};

<script>
$(document).ready(function(){
$(jqn('#lnk.addnote')).click(Notes.add);
});
</script>

But when I click on the "lnk.addnote" link, the dialog is shown and immediately closed. In fact i can see the "ADD FIRED" alert, then the "CREATING DIALOG" alert but nothing appear. And finally I got this message into the Firebug console "$ is not defined".

Can someone help me ?

Thanks